30 Sep C++ Loops

C++ loops execute a block of code and this code executes while the condition is true. Here are the types of loops in C++,

• while loop
• do…while loop
• for loop

Note: Learn how to run your first C++ program in Turbo C++. We will be running the following programs in the same way.

C++ while loop

In the while loop, the block of code executes only when the condition is true. It executes as long as the condition is true.

Here’s the syntax,

while (condition is true)
  statement;

Here’s an example,

#include <iostream.h>
#include <conio.h>
 
void main () {

  int x = 0;

  while( x < 5 ) {
    cout << "x = " << x << "\n";
    x++;
  }

  getch();
}

Here’s the output,

C++ do…while loop

In the do…while loop, the condition is checked at the bottom of the loop. Therefore, the loop executes at least once.

Here’s the syntax:

do{
   statement;
} while(condition);

Here’s an example,

#include <iostream.h>
#include <conio.h>
 
void main () {
   
  int x = 5;

  do {
    cout << "x = " << x << endl;
    x++;
  }while( x <= 10 );
 
  getch();
}

Here’s the output,

C++ for loop

The for loop is used when you can set how many times a statement is to be executed.

Here’s the syntax,

for (initialization; condition; increment) {
  statement;
}

Here’s an example,

Here you can see iterations from x = 5 to x = 10,

#include <iostream.h>
#include <conio.h>
 
void main () {
 
  for( int x = 5; x <= 10; x++) {
    cout << "x = " << x << "\n";
  }
  getch();
}

Here’s the output,